Caterpillar Inc.

Paul C Gottshall

Brian G McGee

Brian L Boggs

Steven O Hart

Long T Le

Paul M Young

Steven R McCoy

James A Antone

Kevin Dee Ehrenhardt

Timothy A Boston

Bahman Gozloo

Ernesto Nicanor Santillan Guerrero

Mike Armstrong

Ulises Ramirez Wleschuver

Ricky L Crebo

A method for remanufacturing an electronic assembly allows the assembly to be disassembled, tested and reassembled despite certain components being permanently affixed to a housing of the assembly. The electronic assembly includes a circuit assembly within the housing. During remanufacture, a first portion of the housing is removed to expose a first side of the circuit assembly and a second portion of the housing is removed to expose a second side of the circuit assembly. When removing the second portion of the housing, one of the components of the circuit assembly may also be removed. During remanufacture a connector assembly including a replacement component substantially similar to the removed component, and including one or more pins connected to the replacement component and situated to mate with one or more empty sockets of the circuit assembly is used to facilitate testing of the assembly.

Remanufacture of electronic assemblies

A method for remanufacturing an electronic assembly includes removing a first portion of an assembly housing to expose an underside of an enclosed circuit assembly. One or more solder joints on the underside of the circuit assembly are associated with at least one component that is also affixed to a portion of the housing. The opened electronic assembly is lowered onto a desoldering fixture having a plurality of solder pots configured to encompass, and thus desolder, the solder joints associated with the component that is affixed to a portion of the housing. Once the affected solder joints are melted, the remaining portion of the housing and the component affixed thereto may be lifted away, exposing the top surface of the circuit assembly for analysis, repair, and or adjustment.

Electronic assembly remanufacturing system and method

A temperature measurement system is provided to measure temperatures using temperature sensors. The temperature measurement system may include a controller having a plurality of address lines, a sensor configured to provide a plurality of inputs, and a connector configured to accept the inputs from the sensor. The temperature measurement system may also include a first multiplexer coupled with at least one input from the sensor and including a plurality of selector lines, and a second multiplexer coupled with one or more other inputs from the sensor and including a plurality of selector lines. The selector lines of the second multiplexer may be respectively coupled to the address lines of the controller. The temperature measurement system may also include a selector logic device coupled between the selector lines of the first multiplexer and the address lines of the controller such that the at least one input coupled to the first multiplexer corresponds to a variable number of inputs from the one or more other inputs coupled to the second multiplexer.

Temperature measurement system and method

A controller area network (CAN) data link is provided including a first node, a second node, and a transformer circuit connected between the first and second nodes to provide electrical isolation. The transformer circuit provides the requisite electrical isolation and is reliable under high temperatures.

Controller area network using transformers

A driver for producing a desired pulse width modulated current through a load has a driver control for storing diagnostics codes in a diagnostic register responsive to detection of at least one electrical fault condition in a circuit including the load. A short circuit detection signal is generated in response a sensed current exceeding a programmed load current range for the driver, whereupon the driver control disables the load current and generates an interrupt signal to a microprocessor. Open circuits and shorts across the load are distinguished by way of a minimum current signal representative of a sensed current flowing through the load exceeding a predetermined minimum.

Fault detection for a pulse width modulation driver

A pulse width modulation driver provides programmable current control for a variety of load current ranges using a modulation feedback block. The block scales a signal representative of a sensed current flowing through the load by a selectable gain multiplier. The scaled signal is compared to a target current value to indicate to a driver control when to generate trigger signals for switching current through the load. In this way, load currents can be amplified to match the operational range of the comparator.

Pulse width modulation driver having programmable current control

A driver for producing a desired pulse width modulated current through a load is provided with a sequencer for generating a plurality of wave forms phase-shifted so as to have non-overlapping duty cycles. A target generator supplies a target current value to a comparator, which compares the target current value to a signal representative of a sensed current flowing through the load. A driver control is responsive to a duty-cycle of only one of the plurality of wave forms to selectively generate trigger signals for switching current through the load in response to the result of the comparison.

Sequencer module for a pulse width modulation driver

A method of calibrating a linear driver system including a linear driver circuit, logic means connected to an input line of the linear driver circuit, and information storage means associated with the logic means, involves testing the linear driver circuit once assembled. A predetermined test load and a test electrical energy source are connected to the linear driver circuit. A first input test voltage is applied to the input line of the linear driver circuit and a corresponding first current level through the test load is measured. A second input test voltage is applied to the input line of the linear driver circuit and a corresponding second current level through the test load is measured. The two measured current levels are stored in the information storage means for later retrieval during operation of the linear driver system.

Method of calibrating a linear driver system

A high side driver circuit includes a command voltage source, a first switching transistor having a base connected to the command voltage source, an emitter connected to ground, and a collector connected to a second switching transistor base. The second switching transistor includes an emitter connected to an electrical energy source through an internal voltage source. A power transistor includes a gate connected to the second switching transistor collector through a resistor, a drain connected to the electrical energy source through a sense resistor, and a source connected to a load. A diagnostic circuit portion including a comparator establishes a diagnostic output voltage based upon the state of the power transistor and characteristics of the power transistor drain and source for indicating fault conditions of the driver circuit.

High side driver circuit with diagnostic output

A method of calibrating an injector driver system including an injector driver circuit, a logic device connected to an input line of the injector driver circuit, and an information storage device associated with the logic device, involves testing the injector driver circuit once assembled. A predetermined test is connected to the injector driver circuit. A pulse width modulated signal having a predetermined duty cycle is applied to the input line of the injector driver circuit and the corresponding current level through the test load is measured. A value indicative of the measured current level is stored in the information storage device for later retrieval during operation of the injector driver system.

Method of calibrating an injector driver system

A low side driver circuit includes a command voltage source, a first switching transistor having a base connected to the command voltage source, an emitter connected to ground, and a collector connected to a second switching transistor base. The second switching transistor includes an emitter connected to a first reference voltage. A power transistor includes a gate connected to the second switching transistor collector through a first resistor, a drain connected to an electrical energy source through a load, and a source connected to ground through a sense resistor. A second resistor is connected between the power transistor gate and ground. A diagnostic circuit portion including a first comparator and a second comparator establishes a diagnostic output voltage based upon the voltages at the power transistor drain, gate and source for indicating fault conditions of the driver circuit.

Low side driver circuit with diagnostic output

In one aspect of the present invention a gate drive circuit is disclosed. The gate drive circuit includes a first voltage source, a power transistor, a first and second switching device, and a controller. The power transistor has a drain connected to the first voltage source and a source connected to a load. The first switching device is connected to the power transistor gate and biases the power transistor ON to transfer energy from the first voltage source to the load. The second switching device is connected to the power transistor gate and biases the power transistor OFF to block the transfer of energy from the first voltage source to the load. The controller is connected to the first and second switching device and controls the power transistor at a first state where the first switching device biases the power transistor ON, controls the power transistor at a second state where the second switching device biases the power transistor OFF and provides a signal path from the power transistor gate to ground, and controls the power transistor at a third state where the second switching device biases the power transistor OFF to protect the second switching device from short circuit voltages in response to the controller detecting a short circuit condition in the power transistor.

Gate drive circuit that controls a power transistor in three states

An apparatus for communicating with an electronic control module on an engine of a machine from a remote location is disclosed. The apparatus includes an electronic controller associated with a power supply on the electronic control module. A sensor is connected to the electronic controller for sensing an engine parameter indicative of the operating state of the engine. A communications interface for transmitting and receiving a communication signal is associated with the electronic controller. An ignition switch is connected to the power supply, such that when the ignition switch is in the off position, the electronic controller is powered down. The electronic controller is subsequently powered up if a communication signal is received from the remote location. This in turn allows a sensed engine parameter to be communicated to the remote location, and further allows machine information to be downloaded from the remote location to the electronic control module while the ignition switch remains in the off position.

Apparatus for communicating with a machine when the machine ignition is

A fuel injector control circuit is disclosed. The circuits can be used with a plurality of different fuel injectors and can be programmed to produce a plurality of different injector current waveforms. The control preferably includes a microprocessor with memory connected to a multiplexer and an application specific integrated circuit. The control can also be used to increase the current rise time of a specific injector current waveform.

Programmable fuel injector current waveform control and method of

An apparatus for sensing the level of fluid, including a two electrode device being disposed in the fluid and a microprocessor. The microprocessor being connected to the two electrode device and delivering alternating current thereto. The microprocessor reads the voltage across the device, compares the voltage to a predetermined voltage level, and produces a warning signal in response to the fluid level being below a predetermined fluid level.

Growing community of inventors

Washington, IL, United States of America

Paul C Gottshall